桂花胚和胚乳发育过程的研究

Studies on Formation and Development of Embryo and Endosperm of Osmanthus fragrans

采用石蜡切片法 ,观察了桂花胚和胚乳的发育过程。结果表明 :桂花胚胎发生类型为柳叶菜型。其卵细胞受精后 ,合子经过一段时间休眠 ,于 10月中、下旬才进行第 1次分裂。合子分裂通常发生在初生胚乳核分裂之后 ,合子经棒形胚、球形胚、心形胚 ,至果实成熟时发育为鱼雷胚。心形胚时期 ,胚柄最为发达。桂花的胚乳发育类型为细胞型。二核胚囊时 ,珠被内层特化为珠被绒毡层 ,球形胚时 ,珠被绒毡层细胞发生形变 ,最后构成种皮的最内层。

Observation on the formation and development of embryo and endosperm of Osmanthus fragrans with stone wax cutting method indicated that the embryo development of sweet Osmanthus was ongrad type. The fertilized egg usually underwent a rest period before embarking on its first division. And the first division of the zygote took place after the division of primary endosperm nucleus. After the club shaped, the globular embryo and the heart shaped embryo, the fish torpedo embryo developed when the fruit became ripe.From the late club shaped to early heart shaped embryo stage, the suspensor grew to its maximum length. The endosperm development of Osmanthus fragrans was cellular type. The endothelium differentiated from the inner epidermis of integument in the period of 2 nucleate embryo sac. The change of endothelium cell shape took place in the period of globular embryo and became the inner seed vessel ultimately.